Support for M335 case light "no case light"

Marlin/Marlin_main.cpp

@@ -7595,22 +7595,27 @@ inline void gcode_M907() {
     analogWrite(CASE_LIGHT_PIN, case_light_on != INVERT_CASE_LIGHT ? case_light_brightness : 0);
   }
 
-  /**
+#endif // HAS_CASE_LIGHT
-   * M355: Turn case lights on/off and set brightness
+
-   *
+/**
-   *   S<bool>  Turn case light on or off
+ * M355: Turn case lights on/off and set brightness
-   *   P<byte>  Set case light brightness (PWM pin required)
+ *
-   */
+ *   S<bool>  Turn case light on or off
-  inline void gcode_M355() {
+ *   P<byte>  Set case light brightness (PWM pin required)
+ */
+inline void gcode_M355() {
+  #if HAS_CASE_LIGHT
     if (code_seen('P')) case_light_brightness = code_value_byte();
     if (code_seen('S')) case_light_on = code_value_bool();
     update_case_light();
     SERIAL_ECHO_START;
     SERIAL_ECHOPGM("Case lights ");
     case_light_on ? SERIAL_ECHOLNPGM("on") : SERIAL_ECHOLNPGM("off");
-  }
+  #else
-
+    SERIAL_ERROR_START;
-#endif // HAS_CASE_LIGHT
+    SERIAL_ERRORLNPGM(MSG_ERR_M355_NONE);
+  #endif // HAS_CASE_LIGHT
+}
 
 #if ENABLED(MIXING_EXTRUDER)
 
@@ -8751,13 +8756,9 @@ void process_next_command() {
 
       #endif // HAS_MICROSTEPS
 
-      #if HAS_CASE_LIGHT
+      case 355: // M355 Turn case lights on/off
-
+        gcode_M355();
-        case 355: // M355 Turn case lights on/off
+        break;
-          gcode_M355();
-          break;
-
-      #endif // HAS_CASE_LIGHT
 
       case 999: // M999: Restart after being Stopped
         gcode_M999();

Marlin/language.h

@@ -153,6 +153,7 @@
 #define MSG_Z2_MAX                          "z2_max: "
 #define MSG_Z_PROBE                         "z_probe: "
 #define MSG_ERR_MATERIAL_INDEX              "M145 S<index> out of range (0-1)"
+#define MSG_ERR_M355_NONE                   "No case light"
 #define MSG_ERR_M421_PARAMETERS             "M421 required parameters missing"
 #define MSG_ERR_MESH_XY                     "Mesh point cannot be resolved"
 #define MSG_ERR_ARC_ARGS                    "G2/G3 bad parameters"